I am curious why you pretty much can't find any mainstream brand of coffee made from Robusto beans - I have never seen a Robusto bean coffee in any grocery store I've ever checked - all 100% Arabica. Seems like with 2x the caffiene there would be a market for it. There are plenty of high-caffiene specialty brands of Arabica - why not just get 2x in the same amount of coffee? Besides, I think the caffiene content they show on the labels is before roasting and the more they roast it, the less caffiene afterwards. There is a misconception that the darker, the more caffiene but its actually the opposite. Just dumb stuff I wonder about...
You can find Deathwish coffee in many grocery stores these days (it’s in most Safeways) and it’s a blend of robusta and arabica beans. Way overpriced with cringey marketing and not the best tasting, but meets your criteria I think
I'm not sure where to find whole beans but I'm pretty sure many brands of instant coffee (e.g. the Folgers and Nescafe of the world) actually use Robusto or at least a blend of Robusto and Arabica.
I bought some unroasted (green) robusta beans from sweetmarias.com and then roasted them. It wasn't bad, but I prefer arabica. It has a more earthy taste. Some espresso blends are part robusta.
